Parasitic Draw Test

[Shortbread69]

Good evening all.

I noticed that my starter battery (2021) discharges over a few days.

sits at 12.65 after a good run, then decreases slowly over a couple of days.

attempted a parasitic draw test but whenever I establish the connection with my multimeter on the negative post / cable I get a module starting a a whirring noise similar to the fuel pump. Should this be happening?

reading at that stage is 3 Amp… so definitely something big drawing on the battery.

is this normal?

should I wait a good while for the engine / system to be fully asleep?

cheers,

G

 

[mmi]

That's normal in that situation.
For proper measurement shouldn't disconnect battery cable as reconnecting boots up several control units. Also the van must be locked, including bonnet latch.
Similar testing here:

Trouble turning over

Hi all I have had an ongoing issue with my van struggling to turn over, this all started towards the end of last year when I went on holiday for 2 weeks. When I returned I started the van and although it started it struggled turning over, I didn't think a lot of it as the van had been stood...

www.t6forum.com

 

[Shortbread69]

Ideal, sorry I did look at a few threads but missed this one.

thank you!

Draw seems to settle at 0.4 after a minute or 2, with the bonnet still opened and everything else closed/off.

will retest with bonnet closed and for a longer period tomorrow.

 

[Dellmassive]

0.4A is 400mA - which is high.

the VW spec is 50mA at sleep max.

above this you will trigger a "quiescent current to high" fault code.

50mA is 0.05A


i use a current clamp on the main battery NEG cable to meter out the current.

Clamp Meters

Any recommendations for clamp meters? They have been mentioned in a few threads but I can’t find suggested products. Suitable for small mA measurements with dc in the van and elsewhere and also if possible up to mains ac. I’m not sure how much I need to spend for a tolerably decent one with the...

www.t6forum.com

.

 

[Dellmassive]

check out the BM2 battery monitor for voltage logging . . .

Battery Monitoring -- How I Done It --

Battery Monitoring -- How I Done It -- Part #1 Battery monitoring is a very important part of your 12v system . . . . whether its just the vans starter battery or your leisure setup keeping an eye on the power in your battery bank will keep you from breaking down and make sure your weekends...

www.t6forum.com

.

 

[Shortbread69]

Cheers sir,

BM2 arriving today, following your advice on other threads.

To be fair, my battery being the wrong type doesn't help either (from my "slow start" thread you also kindly answered to).

 

[Dellmassive]

yes agreed - the starter should be an AGM SLA battery.

OEM is either VARTA or MOL.


other options here:

Upgrading Starter Battery - how to guide

My van (April 2017 T28) is fitted with a Moll battery. I am experiencing some issues with it not starting after a few days sitting on the drive. Now this could be due to the tracker I have fitted draining it but I doubt it, I'll do some drain current tests before taking the plunge. If I were to...

www.t6forum.com

.

 

[Shortbread69]

yes agreed - the starter should be an AGM SLA battery.

OEM is either VARTA or MOL.


other options here:

Upgrading Starter Battery - how to guide

My van (April 2017 T28) is fitted with a Moll battery. I am experiencing some issues with it not starting after a few days sitting on the drive. Now this could be due to the tracker I have fitted draining it but I doubt it, I'll do some drain current tests before taking the plunge. If I were to...

www.t6forum.com

.

Spot on - Will get a new battery, fit the BM2 and monitor.

I'll see if it improves my cold start, cranking, and starter battery charging...

Shame the previous owner just fitted this new lovely incorrect Varta battery back in Feb...